MEMOIR OF LAMARCK. 
33 
tending to destroy it in every Individual necessarily 
brings on Death.” He conceives that the egg, for 
example, contains nothing prepared for life before 
being fecundated, and that the embryo of the chick 
becomes susceptible of vital motion only by the 
action of the seminal vapour ; hut if we admit that 
there exists in the universe a fluid analogous to this 
vapour, and capable of acting upon matter placed 
in favourable circumstances, as in the case of em- 
bryos, we will then be able to form an idea of 
spontaneous generations. The more simple bodies, 
such as a monad or a polypus, arc easily formed ; 
and this being the case, it is easy to conceive how, 
in the lapse of time, animals of more complex 
structure should be produced, for it must be ad- 
mitted as a fundamental law, that the production of 
a new organ in an animal body results from any 
new want or desire which it may experience. The 
first effort of a being just beginning to develope 
itself, must be to procure the means of subsistence, 
and hence in time there came to be produced a 
stomach or alimentary cavity. Other wants, oc- 
casioned by circumstances, will lead to other efforts, 
which in their turn 11111 produce new organs. One 
of the gasteropode mollusc®, for example, may be 
conceived to have felt the necessity, as it moved 
along, of exploring by touch the bodies in its path 
and to have made efforts to do so with some of the 
anterior points of its head, which would continually 
direct to that point masses of the nervous fluid, as 
v ell as other liquids : from these reiterated affluences 
c 
